A member of a group of experts looking into the effects of piscine orthoreovirus (PRV) for the federal government is taking issue with claims that the pathogen poses a “minimal risk” to Fraser River sockeye.

On Thursday, Fisheries and Oceans Canada (DFO) said participants in an expert peer-review process – who are providing the federal department with advice on the virus – had “reached a consensus that the risk to Fraser River sockeye salmon due to PRV is minimal.”

But participant John Werring – who is also part of the steering committee for the peer-review process – says that no such consensus exists.

Too much uncertainty remains about PRV, according to Werring, a senior science and policy adviser with the David Suzuki Foundation.

“The uncertainty is extremely high, and there’s no possible way that we can make any conclusion about the impacts of this pathogen on wild salmon in British Columbia,” Werring said in an interview on Friday. “I don’t think there’s a scientist out there that would argue otherwise.”

Peer review co-chair Gilles Olivier, a former senior official with DFO who is now retired, told reporters on Thursday that a strain of PRV found in B.C. waters is less harmful to Atlantic salmon than one found in Norway, where it originates.

But Werring disputes the claim that PRV isn’t a risk to sockeye.

“They’re uncertain about how long the virus lives, they’re uncertain about how far it spreads, and they’re uncertain about the impact of PRV on other species of salmon,” said Werring, a registered professional biologist with a master’s of science in animal resource ecology.

Claims by DFO about a low risk to sockeye salmon also imply that the virus doesn’t affect wild salmon at all, which isn’t the case, Werring said.

“This is a very narrowly focused, narrowly mandated study,” he added.

Aside from research showing that PRV causes mortality in chinook salmon, he said that unpublished evidence viewed by the peer-review group also points to risks for wild coho and chum salmon.

The peer-review study was restricted to PRV that spreads from fish farms in the Discovery Islands.

“Moving north through the Discovery Islands into the Johnstone Strait and the Queen Charlotte Strait, they’re exposed to 20, 30 other fish farms,” he said. “And that’s not taken into consideration.”

He noted that an email sent out on Wednesday night by Jay Parsons, director of DFO’s Aquaculture, Biotechnology and Aquatic Animal Health Sciences Branch, asked peer-review participants to stick to “agreed-on summary bullets” if approached by the media.

“These summary bullets were not shared with participants prior to the decision to release them, so they were not ‘agreed-on,’” said Werring in an email to the Mirror.

“Had we had the opportunity to review them in advance, it may very well be that we (participants) would have asked for amendments on the overall message. But we were not given that opportunity.”

DFO hasn’t completely ignored uncertainties about PRV science.

A statement from DFO on Thursday acknowledged “there are still some knowledge gaps in our understanding of this virus” and peer-review co-chair Craig Stephen said during the teleconference that a high degree of uncertainty remains about PRV.

The mixed messages from the peer-review group come on the heels of a major legal decision on PRV and the salmon farming industry.

On Monday, the Federal Court of Canada overturned a policy allowing young salmon to be transferred into ocean-based fish farms without first being screened for the virus. This followed lawsuits by ‘Namgis First Nation and by biologist Alexandra Morton, an outspoken critic of open-net fish farms.

Justice Cecily Strickland found that DFO’s threshold for acceptable harm to wild salmon was too high and that its policy didn’t comply with the precautionary principle. The court also found that DFO breached its duty to consult ‘Namgis First Nation about PRV. Strickland gave the federal government four months to review the policy.

DFO declined to comment about its plans during Thursday’s conference call.

A previous version of this article quoted John Werring as saying “there’s no possible way that we can make any conclusion about the impacts of this pathogen on wild salmon in British Columbia…. I don’t think there’s a scientist out there that would argue otherwise, except for DFO.” The words “except for DFO” have been removed because they didn’t capture Werring’s intent.